1. Field of the Invention
The invention relates to a backlight module, and more particularly, to a multi-domain dynamic-driving backlight module.
2. Description of the Related Art
Liquid crystal display devices are already widely used in all kind of electronic devices, such as LCD TVs and computers. Key advantages are low electricity consumption, low driving voltage, and the possibility for electronic devices to be designed with lighter weights and thinner sizes. However, the liquid crystal display panel in the liquid crystal display devices cannot emit light by itself, and have to be paired with a back light unit to light the screen evenly.
Nowadays, LEDs (Light Emitting Diode, hereinafter LED) employed as backlight sources of liquid crystal panels are operated in fully dim or fully bright modes. However, in order to increase contrast characteristics, in a multi-domain dynamic-driving backlight technique, the LEDs are locally controlled depending on an image which is displayed.
Please refer to FIG. 1, which shows a schematic view of a prior art dynamic backlight module 1. LEDs 20A, 20B, and 20C are disposed on the upper, middle, and lower regions of a bezel 10, and the light guide plate 30 is disposed on the middle region of the bezel 10. While a display block A is required to show images, the LED 20B is turned on, and the LEDs 20A and 20C are turned off. However, since the light distribution pattern of the LED can not be effectively concentrated by the light guide plate, a fan-shaped lightened area is formed in display block E. Thus, the desire of local dimming control cannot be fulfilled.